Looks like your lights is just a little too high, this is what s causing your plants to stretch. I also must ask what type of light you are using because I cant see it in the photo. You need to be using either a Metal Halide or a flourescent light for the vegetative state, these lights provide the plant with the proper spectrum of light. If your are just using plain water now thats ok, but your plants are getting to the age when they will start to need nutrient. I recomend that you go pick up some nutrients. Your plants are still a fair ways away from the flowering stage (12/12), Id let them grow to atleast 30 inch's before I would turn the lights to 12/12. As for a new light, if you cant find one in your small town order online. I recomend ordering from this website
http://homeharvest.com/ They ship everywhere and have a very broad selection of grow lights and brands. Hope this Information is useful. HAPPY GROWING !!!!!
P.S. You may need to let your plants get a little bigger than 30 inches because of the stretching. You want your plant to be bushy and lush with foliage with as little of space between the internodes as possible. If your plant is 30 inches and bushy it would be a pretty good time to flower becuase the plant will stretch a foot or two in the flowering stage.